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Calling Shenanigans on IDC Numbers

October 20, 2008 Leave a Comment

Over the years of playing the Technology Vendor game, I have learned not to give too much attention to IT Analysts statistics. This comes from understanding of how the Analysts’ game is usually played from dealing with them from both the end user client and IT vendor perspective. So when I come across statistics, I usually glance at them and move along. This morning, however, when I came across IDC’s Worldwide Quarterly Server Virtualization Tracker press release (thanks to virtualization.com’s recent post) I had to stop and take a deeper look.

The single line that made me stop was (emphasis mine):

However, in its first quarter of general availability Microsoft Hyper-V delivered a strong showing, and when combined with Virtual Server 2005, Microsoft’s market share is 23% of new shipments.

It was the two phrases in red that makes me call Shenanigans on this data.

First, this report is for the second calendar quarter of 2008 (April, May, June). Hyper-V was release just a few days before the end of June; see Microsoft’s Hyper-V press release announcing availability date on June 26. My first reaction to this point was one of disbelief that any company, even Microsoft, could go from zero to 23% market share in three business days (Thursday June 26, Friday June 27th, and Monday June 30th).

Second, the nuance of what products were included shed light on how that amazing growth happened. The report didn’t just count Hyper-V shipments, but also Virtual Server 2005. It also didn’t indicate if the Hyper-V shipments that were counted included betas that would have been in use well before the release of the product. This artificially inflated market share numbers skews the perception of this part of the report.

This leads me to wonder why the numbers were skewed this way in the first place. Was IDC just looking for some big bang to be able to report on to drive sales of the report and their own corporate visibility? Or was Microsoft involved in some way in the generation of this report and influenced the skewing of these numbers?

Wouldn’t it be nice to have this level of transparency from an Analyst with regards to their reports? Why not show us the break down numbers of just ESX and Hyper-V shipments?

(Disclaimer: I am currently employed at VMware as a Solutions Consultant)

Server Consolidation and VM Sprawl

October 2, 2008 Leave a Comment

Today I came across Mike DiPetrillo’s article on Virtual Server Sprawl and found it very reminiscent of issues that I see in my enterprise customers while they are undergoing server consolidation. Virtualization is almost always part of any server consolidation effort today. Yet, there are some companies who, for various reasons, do not think about virtualization during consolidation…they think of it after consolidation. While virtualization during consolidation takes more effort and planning than consolidation alone, there ends up being more waste in time, resources, and capital when virtualization is done after. Unless you’re undergoing a huge enterprise wide consolidation or consolidation of Tier 1 applications, think consolidation and virtualization together.

When you do think about both, make sure that you take into consideration the cultural or social changes in your organization that virtualization may make. If your pulling developers systems out from under their desk and giving them VMs, there will be some resistance just because they feel like they are loosing something.

But, once the benefits of virtualization is discovered, make sure you don’t short change yourself on two fronts:

Storage: Many an IT manager has short changed themselves on storage during a virtualization effort. Either by purchasing lower grade storage that costs less at the expense of performance or by not buying enough storage. With all the VMs running off of a shared storage device performance needs to be kept in the forefront of your planning. Also, once the users start to realize the benefits of virtualization the potential for VM sprawl starts as does the depletion of your storage.
Workflow: One of the often overlooked areas of a virtualization deployment is the process and workflow around requesting and authorizing new VMs. This is what leads to VM sprawl and quickly depleted resources. This is also exactly where VMware Lifecycle Manager (LCM) comes into play. You need to think about how groups will request new VMs and the authorization process needed to approve them. LCM will help with all that.

Just a few items to keep in mind while planning a consolidation or a virtualization effort.

ESX Performance Discussion and Tips

September 22, 2008 Leave a Comment

Last week, before the end of VMworld, we had a session with one of my customer’s to discuss ESX performance. This discussion was lead by one of VMware’s performance gurus Scott Drummonds. Scott works as the Manager of VMware’s Performance Marketing team, working with the VMware field teams and customers to provide and advise on product performance issues.

During this conversation, I wrote down some key quotes from Scott that I wanted to share. For those that have been around VMTN for a while, you might already know some or all of these performance related suggestions. However, they are key enough that I wanted to draw attention to them.

“Administration work on the LUN has an impact on performance more than the number of hosts.”

When admin work is done on the LUN is the only time that SCSI reservation locking is used. So placing more VMDKs on the same LUN doesn’t directly impact the performance. See Scalable Storage Performance with VMware ESX Server 3.5 Vroom! blog post for additional details.

“Put Windows VMs and Linux VMs in sperate clusters because they can share memory more efficiently…”

Part of the memory optimization doen within the ESX hyperadvisor is to share common memory used by multiple VMs. So if you are running 10 Windows VM, the memory used to store the majority of the Windows OS is shared amonst all 10 VMs since the memory contents are the same and do not change. This is what enables memory overcommitting. If you start to mix and match different OS VMs on the same host, this advantage can be minimized.

“High storage latencies is the largest source of performance problems that I see…”

You can monitor the storage latencies within VC by changing the stats level. See Scott’s Understanding VirtualCenter Performance Statistics performance community doc for more details.

“Once your swapping, you’re in trouble…”

Seeing swapping within your VM means that you are not allocating enough memory to the VM for the applications that are running. Watch this closely and add memory or migrate VMs when and where needed.

“RHEL5 does 1000 interrupts per second for “greater precision” (versus most OS’ which only do 100) which can add up to un-wanted overhead in the OS…”

This is an issue with the Linux Timer Rates that Scott talks about. There is a small configuration change that you can make in RHEL5 SMP that will provide an across the board increase in system performance.

Check out all of Scott’s VMTN articles, there is a wealth of information in them.